What Do Investors Look For in a Code Audit? The Due Diligence Checklist

You're raising capital. The term sheet looks good. Then the investor says: "We'll need to do technical due diligence."

What exactly are they going to look for? And more importantly — what will make them walk away?

This guide covers exactly what investors examine during technical due diligence, based on patterns from hundreds of startup audits.

The 7 Things Investors Check

1. Exposed Secrets and Credentials

What they look for:

• API keys hardcoded in source files
• Database passwords in config files
• AWS/GCP credentials committed to git
• .env files in version control
• Secrets in git history (even if deleted)

Why it matters: Exposed secrets are the #1 red flag. They signal poor security hygiene and create immediate liability. One leaked AWS key can result in a six-figure bill from crypto miners.

The stat that scares investors:

35% of private repositories contain at least one exposed secret (GitGuardian 2026)

How to prepare: Run a secrets scan before investors do. Tools like SystemAudit, GitGuardian, or truffleHog can find exposed credentials instantly.

2. Dependency Vulnerabilities

What they look for:

• Outdated packages with known CVEs
• Dependencies with critical security advisories
• Unmaintained libraries (no updates in 2+ years)
• Dependency confusion risks

Why it matters: 87% of codebases contain at least one known vulnerability in their dependencies (Synopsys 2026). Investors know this — they want to see you're actively managing the risk.

Red flags:

• Log4j still unpatched
• Dependencies 3+ major versions behind
• No lock file (package-lock.json, yarn.lock)
• Hundreds of dependencies for a simple app

How to prepare: Run npm audit, pip-audit, or your package manager's security check. Fix critical and high severity issues. Document known issues you're accepting.

3. Code Architecture and Scalability

What they look for:

• Can this system handle 10x users?
• Is the architecture sensible or spaghetti?
• Are there obvious bottlenecks?
• Is it a monolith that should be, or microservices that shouldn't be?

Why it matters: Investors are betting on growth. If your architecture can't scale without a rewrite, that's a hidden cost they need to factor in.

What impresses them:

• Clear separation of concerns
• Documented architecture decisions
• Evidence of load testing or capacity planning
• Sensible database design

What concerns them:

• Everything in one file
• No clear structure
• Database queries in UI components
• "We'll refactor later" everywhere

4. Test Coverage and CI/CD

What they look for:

• Does automated testing exist?
• What's the coverage percentage?
• Is there a CI/CD pipeline?
• How confident is the team in deploying?

Why it matters: No tests = every change is risky. Risky changes = slow development. Slow development = missed market windows.

Reality check: You don't need 100% coverage. But having zero tests signals that the team is either moving too fast or doesn't value quality. Neither is good.

Minimum viable testing:

• Unit tests on critical business logic
• Integration tests on key user flows
• CI pipeline that runs tests on every PR
• Ability to rollback bad deploys

5. Technical Debt Inventory

What they look for:

• How much debt exists?
• Does the team know about it?
• Is there a plan to address it?
• Is it intentional (shortcuts for speed) or accidental (nobody noticed)?

Why it matters: Every codebase has technical debt. The question is whether it's managed or ignored. Investors worry about the debt they can't see.

Green flags:

• TODO comments with ticket numbers
• Technical debt documented somewhere
• Regular time allocated for cleanup
• Honest answers about shortcuts taken

Red flags:

• "What technical debt?"
• TODOs from 3 years ago
• Dead code nobody understands
• Features everyone's afraid to touch

6. Security Practices

What they look for:

• Authentication implementation
• Authorization and access control
• Data encryption (at rest and in transit)
• Input validation and sanitization
• Logging and audit trails

Why it matters: A security breach can kill a startup. Investors want to know you're not one SQL injection away from disaster.

Common issues found:

• No rate limiting on APIs
• Passwords stored in plain text (yes, still happens)
• Missing HTTPS enforcement
• Admin panels with no authentication
• User data logged in plain text

7. Documentation and Onboarding

What they look for:

• Can a new developer understand this?
• Is there a README that actually helps?
• Are there architecture docs?
• How long to onboard a senior engineer?

Why it matters: Investors are funding growth. Growth means hiring. If onboarding takes 3 months, hiring becomes a bottleneck.

What they want to see:

• README with setup instructions that work
• High-level architecture diagram
• API documentation (even auto-generated)
• Runbooks for common operations

What Makes Investors Walk Away?

Not every issue is a deal-breaker. Here's what actually kills deals:

Issues That Reduce Valuation (But Don't Kill Deals)

How to Prepare for Technical Due Diligence

2-4 Weeks Before Due Diligence

1. Run a security scan

   • Find and rotate exposed secrets
   • Update critical dependencies
   • Fix obvious vulnerabilities

2. Document what you know

   • Architecture overview (even a napkin sketch helps)
   • Known technical debt with remediation plan
   • Deployment and rollback process

3. Clean up the obvious

   • Remove dead code
   • Delete commented-out blocks
   • Organize chaotic directories

1 Week Before

1. Do a self-audit

   • Run the same tools investors will use
   • SystemAudit.dev gives you investor-perspective results in minutes
   • Know your numbers before they do

2. Prepare honest answers

   • "What's the hardest part of the codebase?"
   • "What would you fix with 3 months and 2 engineers?"
   • "What keeps you up at night technically?"

3. Brief your technical team

   • They'll likely be interviewed
   • Honesty > defensiveness
   • Knowing issues signals maturity

What Investors Actually Ask in Technical Interviews

Expect these questions for your CTO or lead engineer:

Architecture:

• "Walk me through how a request flows through your system"
• "What happens when this service goes down?"
• "How would you handle 10x current traffic?"

Process:

• "How do you deploy to production?"
• "What does your code review process look like?"
• "How do you handle incidents?"

Debt:

• "What would you rebuild if you could start over?"
• "Where are the bodies buried?"
• "What's your biggest technical regret?"

Team:

• "How would the team function if you left?"
• "What's the bus factor on critical systems?"
• "How do you onboard new engineers?"

Run Your Own Audit First

Don't wait for investors to find problems. Find them yourself.

SystemAudit.dev gives you the same view investors will have:

• Security scan for exposed secrets and vulnerabilities
• Architecture map showing system structure
• AI readiness grade across 5 dimensions
• Plain-English findings you can act on

Frequently Asked Questions

How long does technical due diligence take?

Typically 1-3 weeks for Series A, longer for acquisitions. Automated tools can give you a preliminary view in minutes, which often determines whether deeper review is needed.

Can I fail technical due diligence?

Yes. Severe findings (exposed production databases, fundamental security flaws, or discovering the code doesn't match what was described) can kill deals. More often, issues result in valuation adjustments or protective terms.

Should I proactively share a technical assessment?

Many founders do. It demonstrates transparency and technical maturity. It also lets you control the narrative rather than having investors discover issues themselves.

What if we used a lot of AI-generated code?

Investors increasingly ask about this. The concerns are: code quality, security vulnerabilities (40% of AI code has flaws per Stanford research), and maintainability. Be honest about AI usage and show you've reviewed it.

Bottom Line

Investors aren't looking for perfect code. They're looking for:

1. No landmines — Nothing that could blow up the company
2. Self-awareness — Team knows what's wrong and has a plan
3. Reasonable quality — Code that can scale with the business
4. Security basics — No obvious breaches waiting to happen

The best founders know their codebase better than any auditor. They've already found the issues, prioritized fixes, and can speak confidently about technical tradeoffs.

That's what investors actually want to see.

Related reading:

• How Much Does a Code Audit Cost?
• Technical Due Diligence: What Investors Check
• Code Audit Checklist
• Find Exposed Secrets in GitHub